1. Field of the Invention
The present invention relates to a filler device or filler pipe for guiding fuel into a fuel tank from a fuel gun.
2. Related Art
The filler device couples an inside of an inlet box and an internal space of the fuel tank so as to communicate therebetween. An upstream end of the filler device is projected in the inlet box. A pouring inlet is formed on the upstream end of the filler device. The fuel provided from the fuel gun is injected into the fuel tank through an inside of the filler device.
As such the filler devices, a resin inlet pipe on which a bellows part is formed is conventionally known. Although this inlet pipe is advantageous in its lightweight and flexibility for arrangement, the bellows part can result in a high flow resistance in feeding the fuel, disturbing a smooth filling operation.
To solve the above problem, as shown in Japanese patent publication No. JP 2000-85381, it is known that a flat portion is formed on a part of the bellows part on which the fuel comes into abutment in the filling operation. However, flexibility of the pipe is decreased by providing the flat portion partially formed on the bellows part and the arrangement of the pipe becomes more limited.
Further, in order to reduce the flow resistance, it is also known a double tubular structure, in which a straight tube is inserted in the inside of the bellows part while not being fixed, as shown in Japanese Utility Model Publication No. JP H02-36687U. However, the tube having the double tubular structure has not been studied in detail for the application to the inlet pipe, conventionally.
Japanese patent publication JP 2000-159296A and Japanese utility model publication JP S60-165219U disclose filler devices in which an inner diameter of the filler device varies along a longitudinal direction of the device. A filler device as shown in these publications is provided with a first larger diameter section, a smaller diameter section and a second larger diameter section from the upstream side to the downstream side. In such the filler device, the fuel is provided in the first larger diameter section at first, and then it is narrowed in the smaller diameter section. The fuel is diffused again by the second larger diameter section.
In the filler devices, the pipe is often curved downwardly in a vicinity of the pouring inlet due to the arrangement of the pipe between the inlet box and the fuel tank. When the fuel ejected from the fuel gun comes into abutment on such the curved part of the pipe, and bounces back toward the pouring inlet. Therefore, the fuel is not fed easily to the filler device from the fuel gun. In other words, the fuel is not well introduced into the filler device.
In cases of the filler devices shown in JP 2000-159296A and JP S60-165219U, the fuel ejected from the fuel gun is fed into the first larger diameter section at first. Accordingly, the fuel is rapidly diffused from the leading end of the fuel gun to an inner passage of the first larger diameter section. If a curved part is arranged in a middle of the first larger diameter section, the flow of fuel abuts with the curved part while being diffused. In this case, the fuel can bounce back more easily. Therefore, the introduction of the fuel to the filler device becomes even worse.